Standards as High as Your Own
NECA Online Help Desk Please leave a message
I currently have 220 vac - 2 wire Aluminum Service Entrance Cable with AL braid from the service transformer outside to a 600A disconnect inside (basement) The AL braid is used as the neutral conductor which I understand is acceptable from the transformer to the Disconnect. My question is .......Is it acceptable to use Aluminum Service Entrance Cable and the AL braid .From the Disconnect to the Service Panel or should the neutral be an insulated conductor. Service cable runs are in non-metallic conduit.
Thanks, John Barkley
Hey John thanks for your question. Aluminum service entrance grounded conductors (usually also neutral conductors), that are part of a cable assembly (such as SE-U), are allowed to be uninsulated as stated in 230.41Exception (4). The disconnect inside the basement is your service equipment, if I understand your example correctly, the conductors from it to a panelboard are feeders. See the definitions of Service Entrance Conductors, Underground System, Grounded Conductor, Neutral Conductor, and Service Equipment in Article 100 to help explain those terms. Grounded conductors that are part of Service Entrance Cable - Type SE used for feeders and branch circuits must be insulated (such as SE-R) as stated in 338.10(B)(1). Type SE cable is also not allowed underground - whether or not in a raceway, as stated in 338.12(A)(2). Make sure you are not using USE cable because it is not allowed inside buildings as stated in 338.12(B), unless it is also marked with another insulation type that is suitable.
ABOUT CQD: NECA’s Code Question of the Day (CQD) is a leading National Electrical Code® forum for NECA and the industry. The CQD generates a lively dialogue and relative practical and Code-based responses to an ever-increasing and interactive audience.
IMPORTANT NOTICE: All answers are based on the latest edition of the National Electrical Code®, unless the question requests a response based on a specific edition. This correspondence is not a formal interpretation of the NEC®. Any responses expressed to the questions are opinions and do not necessarily represent the official position of NECA, NFPA, or any technical committee. In addition, this correspondence is neither intended, nor should it be relied upon, to provide professional consultation or services.
ABOUT CHARLIE: Charles M. Trout, better known as Charlie, was a nationally known NEC® expert and author. He served on several NEC® technical committees and is past chairman of CMP-12. In 2006 Charlie was awarded the prestigious Coggeshall Award for outstanding contributions to the electrical contracting industry, codes and standards development, and technical training. Charlie was also a member of NECA’s Academy of Electrical Contracting. Charlie’s experienced team of industry experts keep the CQD dialogue and discussions active and informative in the spirit of the man himself, as he wanted.
NECA STANDARDS: NECA publishes the National Electrical Installation Standards™ (NEIS™), a series of ANSI-approved performance and quality standards for electrical construction. Visit NECA-NEIS.org for more information. NEISÃ” can be purchased in three formats: as paper books, on CD, or as electronic downloads.
NECA SAFETY PRODUCTS: NECA publishes valuable electrical safety books and CDs for the industry. Visit necanet.org/store to view or purchase NECA safety products.
CONTACT US: To submit a Code question, subscribe, or unsubscribe from this list, please e-mail: email@example.com.
© 1999 – 2014 National Electrical Installation Standards. All rights reserved.
Brought to you by NECA. NECA is the voice of the electrical contracting industry NATIONAL ELECTRICAL INSTALLATION STANDARDS, NEIS and the NEIS logo are registered trademarks of the National Electrical Contractors Association.
Created by Matrix Group International, Inc.